/*
 * EMS-ESP - https://github.com/emsesp/EMS-ESP
 * Copyright 2020-2023  Paul Derbyshire
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "mqtt.h"
#include "emsesp.h"
#include "version.h"
#include "emsdevice.h"

namespace emsesp {

MqttClient * Mqtt::mqttClient_;

// static parameters we make global
std::string Mqtt::mqtt_base_;
std::string Mqtt::mqtt_basename_;
uint8_t     Mqtt::mqtt_qos_;
bool        Mqtt::mqtt_retain_;
uint32_t    Mqtt::publish_time_boiler_;
uint32_t    Mqtt::publish_time_thermostat_;
uint32_t    Mqtt::publish_time_solar_;
uint32_t    Mqtt::publish_time_mixer_;
uint32_t    Mqtt::publish_time_sensor_;
uint32_t    Mqtt::publish_time_other_;
uint32_t    Mqtt::publish_time_heartbeat_;
bool        Mqtt::mqtt_enabled_;
uint8_t     Mqtt::entity_format_;
bool        Mqtt::ha_enabled_;
uint8_t     Mqtt::nested_format_;
std::string Mqtt::discovery_prefix_;
uint8_t     Mqtt::discovery_type_;
bool        Mqtt::send_response_;
bool        Mqtt::publish_single_;
bool        Mqtt::publish_single2cmd_;

std::vector<Mqtt::MQTTSubFunction> Mqtt::mqtt_subfunctions_;

uint32_t Mqtt::mqtt_publish_fails_ = 0;
bool     Mqtt::connecting_         = false;
bool     Mqtt::initialized_        = false;
bool     Mqtt::ha_climate_reset_   = false;
uint16_t Mqtt::queuecount_         = 0;
uint8_t  Mqtt::connectcount_       = 0;
uint32_t Mqtt::mqtt_message_id_    = 0;
char     will_topic_[Mqtt::MQTT_TOPIC_MAX_SIZE]; // because MQTT library keeps only char pointer

std::string Mqtt::lasttopic_    = "";
std::string Mqtt::lastpayload_  = "";
std::string Mqtt::lastresponse_ = "";

// Home Assistant specific
// icons from https://materialdesignicons.com used with the UOMs (unit of measurements)
MAKE_WORD(measurement)
MAKE_WORD(total_increasing)
MAKE_WORD_CUSTOM(icondegrees, "mdi:coolant-temperature") // DeviceValueUOM::DEGREES
MAKE_WORD_CUSTOM(iconpercent, "mdi:percent-outline")     // DeviceValueUOM::PERCENT
MAKE_WORD_CUSTOM(iconkb, "mdi:memory")                   // DeviceValueUOM::KB
MAKE_WORD_CUSTOM(iconlmin, "mdi:water-boiler")           // DeviceValueUOM::LMIN
MAKE_WORD_CUSTOM(iconua, "mdi:lightning-bolt-circle")    // DeviceValueUOM::UA
MAKE_WORD_CUSTOM(iconnum, "mdi:counter")                 // DeviceValueUOM::NONE

uuid::log::Logger Mqtt::logger_{F_(mqtt), uuid::log::Facility::DAEMON};

// subscribe to an MQTT topic, and store the associated callback function
// only if it already hasn't been added
// topics exclude the base
void Mqtt::subscribe(const uint8_t device_type, const std::string & topic, mqtt_sub_function_p cb) {
    // check if we already have the topic subscribed for this specific device type, if so don't add it again
    // add the function (in case its not there) and quit because it already exists
    if (!mqtt_subfunctions_.empty()) {
        for (auto & mqtt_subfunction : mqtt_subfunctions_) {
            if ((mqtt_subfunction.device_type_ == device_type) && (strcmp(mqtt_subfunction.topic_.c_str(), topic.c_str()) == 0)) {
                if (cb) {
                    mqtt_subfunction.mqtt_subfunction_ = cb;
                }
                return; // exit - don't add
            }
        }
    }

    // register in our libary with the callback function.
    // We store the original topic string without base
    mqtt_subfunctions_.emplace_back(device_type, std::move(topic), std::move(cb));

    if (!enabled() || !connected()) {
        return;
    }

    // add to MQTT queue as a subscribe operation
    queue_subscribe_message(topic);
}

// subscribe without storing to subfunctions
void Mqtt::subscribe(const std::string & topic) {
    // add to MQTT queue as a subscribe operation
    queue_subscribe_message(topic);
}

// resubscribe to all MQTT topics
// if it's already in the queue then just ignore it
void Mqtt::resubscribe() {
    if (mqtt_subfunctions_.empty()) {
        return;
    }

    for (const auto & mqtt_subfunction : mqtt_subfunctions_) {
        queue_subscribe_message(mqtt_subfunction.topic_);
    }
}

// Main MQTT loop - sends out top item on publish queue
void Mqtt::loop() {
    queuecount_ = mqttClient_->queueSize();

    // exit if MQTT is not enabled or if there is no network connection
    if (!connected()) {
        return;
    }

    uint32_t currentMillis = uuid::get_uptime();

    // send heartbeat
    if ((currentMillis - last_publish_heartbeat_ > publish_time_heartbeat_)) {
        last_publish_heartbeat_ = currentMillis;
        EMSESP::system_.send_heartbeat(); // send heartbeat
    }

    // temperature and analog sensor publish on change
    if (!publish_time_sensor_) {
        EMSESP::publish_sensor_values(false);
    }

    // wait for empty queue before sending scheduled device messages
    if (queuecount_ > 0) {
        return;
    }

    // create publish messages for each of the EMS device values, adding to queue, only one device per loop
    if (publish_time_boiler_ && (currentMillis - last_publish_boiler_ > publish_time_boiler_)) {
        last_publish_boiler_ = (currentMillis / publish_time_boiler_) * publish_time_boiler_;
        EMSESP::publish_device_values(EMSdevice::DeviceType::BOILER);
    } else

        if (publish_time_thermostat_ && (currentMillis - last_publish_thermostat_ > publish_time_thermostat_)) {
        last_publish_thermostat_ = (currentMillis / publish_time_thermostat_) * publish_time_thermostat_;
        EMSESP::publish_device_values(EMSdevice::DeviceType::THERMOSTAT);
    } else

        if (publish_time_solar_ && (currentMillis - last_publish_solar_ > publish_time_solar_)) {
        last_publish_solar_ = (currentMillis / publish_time_solar_) * publish_time_solar_;
        EMSESP::publish_device_values(EMSdevice::DeviceType::SOLAR);
    } else

        if (publish_time_mixer_ && (currentMillis - last_publish_mixer_ > publish_time_mixer_)) {
        last_publish_mixer_ = (currentMillis / publish_time_mixer_) * publish_time_mixer_;
        EMSESP::publish_device_values(EMSdevice::DeviceType::MIXER);
    } else

        if (publish_time_other_ && (currentMillis - last_publish_other_ > publish_time_other_)) {
        last_publish_other_ = (currentMillis / publish_time_other_) * publish_time_other_;
        EMSESP::publish_other_values(); // switch and heatpump
    } else

        if (publish_time_sensor_ && (currentMillis - last_publish_sensor_ > publish_time_sensor_)) {
        last_publish_sensor_ = (currentMillis / publish_time_sensor_) * publish_time_sensor_;
        EMSESP::publish_sensor_values(true);
    }
}

// print MQTT log and other stuff to console
void Mqtt::show_mqtt(uuid::console::Shell & shell) {
    shell.printfln("MQTT is %s", connected() ? F_(connected) : F_(disconnected));
    shell.printfln("MQTT Entity ID format is %d", entity_format_);

    shell.printfln("MQTT publish errors: %lu", mqtt_publish_fails_);
    shell.printfln("MQTT queue: %d", queuecount_);
    shell.println();

    // show subscriptions
    shell.printfln("MQTT topic subscriptions:");
    for (const auto & mqtt_subfunction : mqtt_subfunctions_) {
        shell.printfln(" %s/%s", Mqtt::base().c_str(), mqtt_subfunction.topic_.c_str());
    }
    shell.println();

    shell.println();
}

#if defined(EMSESP_TEST)
// simulate receiving a MQTT message, used only for testing
void Mqtt::incoming(const char * topic, const char * payload) {
    if (payload != nullptr) {
        on_message(topic, (const uint8_t *)payload, strlen(payload));
    }
}
#endif

// received an MQTT message that we subscribed too
// topic is the full path
// payload is json or a single string and converted to a json with key 'value'
void Mqtt::on_message(const char * topic, const uint8_t * payload, size_t len) {
    // the payload is not terminated
    // convert payload to a null-terminated char string
    // see https://www.emelis.net/espMqttClient/#code-samples
    char message[len + 1];
    memcpy(message, payload, len);
    message[len] = '\0';

#if defined(EMSESP_DEBUG)
    if (len) {
        LOG_DEBUG("Received topic `%s` => payload `%s` (length %d)", topic, message, len);
    } else {
        LOG_DEBUG("Received topic `%s`", topic);
    }
#endif
    // remove HA topics if we don't use discovery
    if (strncmp(topic, discovery_prefix().c_str(), discovery_prefix().size()) == 0) {
        if (!ha_enabled_ && len) { // don't ping pong the empty message
            queue_publish_message(topic, "", true);
            LOG_DEBUG("Remove topic %s", topic);
        }
        return;
    }

    // for misconfigured mqtt servers and publish2command ignore echos
    if (publish_single_ && publish_single2cmd_ && lasttopic_ == topic && lastpayload_ == message) {
        LOG_DEBUG("Received echo message %s: %s", topic, message);
        return;
    }

    // check first against any of our subscribed topics
    for (const auto & mf : mqtt_subfunctions_) {
        // add the base back
        char full_topic[MQTT_TOPIC_MAX_SIZE];
        snprintf(full_topic, sizeof(full_topic), "%s/%s", Mqtt::base().c_str(), mf.topic_.c_str());

        if ((!strcmp(topic, full_topic)) && (mf.mqtt_subfunction_)) {
            if (!(mf.mqtt_subfunction_)(message)) {
                LOG_ERROR("error: invalid payload %s for this topic %s", message, topic);
                Mqtt::queue_publish("response", "error: invalid data");
            }
            return;
        }
    }

    StaticJsonDocument<EMSESP_JSON_SIZE_SMALL> input_doc;
    DynamicJsonDocument                        output_doc(EMSESP_JSON_SIZE_XLARGE);
    JsonObject                                 input, output;

    // convert payload into a json doc
    // if the payload doesn't not contain the key 'value' or 'data', treat the whole payload as the 'value'
    if (len != 0) {
        DeserializationError error = deserializeJson(input_doc, (const char *)message);
        if ((!input_doc.containsKey("value") && !input_doc.containsKey("data")) || error) {
            input_doc.clear();
            input_doc["value"] = (const char *)message; // always a string
        }
    }

    // parse and call the command
    input               = input_doc.as<JsonObject>();
    output              = output_doc.to<JsonObject>();
    uint8_t return_code = Command::process(topic, true, input, output); // mqtt is always authenticated

    if (return_code != CommandRet::OK) {
        char error[100];
        if (output.size()) {
            snprintf(error,
                     sizeof(error),
                     "MQTT command failed with error: %s (%s)",
                     (const char *)output["message"],
                     Command::return_code_string(return_code).c_str());
        } else {
            snprintf(error, sizeof(error), "MQTT command failed with error code (%s)", Command::return_code_string(return_code).c_str());
        }
        LOG_ERROR(error);
        Mqtt::queue_publish("response", error);
    } else {
        // all good, send back json output from call
        Mqtt::queue_publish("response", output);
    }
}

// print all the topics related to a specific device type
void Mqtt::show_topic_handlers(uuid::console::Shell & shell, const uint8_t device_type) {
    if (std::count_if(mqtt_subfunctions_.cbegin(),
                      mqtt_subfunctions_.cend(),
                      [=](MQTTSubFunction const & mqtt_subfunction) { return device_type == mqtt_subfunction.device_type_; })
        == 0) {
        return;
    }

    // shell.print(" Subscribed MQTT topics: ");
    // for (const auto & mqtt_subfunction : mqtt_subfunctions_) {
    //     if (mqtt_subfunction.device_type_ == device_type) {
    //         shell.printf("%s ", mqtt_subfunction.topic_.c_str());
    //     }
    // }
    shell.println();
}

// called when an MQTT Publish ACK is received
void Mqtt::on_publish(uint16_t packetId) const {
    LOG_DEBUG("Packet %d sent successful", packetId);
}

// called when MQTT settings have changed via the Web forms
void Mqtt::reset_mqtt() {
    if (!mqttClient_) {
        return;
    }

    if (mqttClient_->connected()) {
        mqttClient_->disconnect(true); // force a disconnect
    }
}

// load the settings from service
void Mqtt::load_settings() {
    EMSESP::esp8266React.getMqttSettingsService()->read([&](MqttSettings & mqttSettings) {
        mqtt_base_          = mqttSettings.base.c_str(); // Convert String to std::string
        mqtt_qos_           = mqttSettings.mqtt_qos;
        mqtt_retain_        = mqttSettings.mqtt_retain;
        mqtt_enabled_       = mqttSettings.enabled;
        ha_enabled_         = mqttSettings.ha_enabled;
        nested_format_      = mqttSettings.nested_format;
        publish_single_     = mqttSettings.publish_single;
        publish_single2cmd_ = mqttSettings.publish_single2cmd;
        send_response_      = mqttSettings.send_response;
        discovery_prefix_   = mqttSettings.discovery_prefix.c_str();
        entity_format_      = mqttSettings.entity_format;
        discovery_type_     = mqttSettings.discovery_type;

        // convert to milliseconds
        publish_time_boiler_     = mqttSettings.publish_time_boiler * 1000;
        publish_time_thermostat_ = mqttSettings.publish_time_thermostat * 1000;
        publish_time_solar_      = mqttSettings.publish_time_solar * 1000;
        publish_time_mixer_      = mqttSettings.publish_time_mixer * 1000;
        publish_time_other_      = mqttSettings.publish_time_other * 1000;
        publish_time_sensor_     = mqttSettings.publish_time_sensor * 1000;
        publish_time_heartbeat_  = mqttSettings.publish_time_heartbeat * 1000;
    });

    // create basename from the mqtt base
    // and replacing all / with underscores, in case it's a path
    mqtt_basename_ = mqtt_base_;
    std::replace(mqtt_basename_.begin(), mqtt_basename_.end(), '/', '_');
}

// start mqtt
void Mqtt::start() {
    mqttClient_ = EMSESP::esp8266React.getMqttClient();

    load_settings(); // fetch MQTT settings

    if (!mqtt_enabled_) {
        return; // quit, not using MQTT
    }

    // if already initialized, don't do it again
    // also to prevent duplicated loading from MqttSettingsService::onConfigUpdated()
    if (initialized_) {
        return;
    }
    initialized_ = true;

    // add the 'publish' command ('call system publish' in console or via API)
    Command::add(EMSdevice::DeviceType::SYSTEM, F_(publish), System::command_publish, FL_(publish_cmd));

    // create last will topic with the base prefixed. It has to be static because asyncmqttclient destroys the reference
    static char will_topic[MQTT_TOPIC_MAX_SIZE];
    if (!Mqtt::base().empty()) {
        snprintf(will_topic, MQTT_TOPIC_MAX_SIZE, "%s/status", Mqtt::base().c_str());
    } else {
        snprintf(will_topic, MQTT_TOPIC_MAX_SIZE, "status");
    }

    EMSESP::esp8266React.setWill(will_topic); // with qos 1, retain true
}

void Mqtt::set_publish_time_boiler(uint16_t publish_time) {
    publish_time_boiler_ = publish_time * 1000; // convert to milliseconds
}

void Mqtt::set_publish_time_thermostat(uint16_t publish_time) {
    publish_time_thermostat_ = publish_time * 1000; // convert to milliseconds
}

void Mqtt::set_publish_time_solar(uint16_t publish_time) {
    publish_time_solar_ = publish_time * 1000; // convert to milliseconds
}

void Mqtt::set_publish_time_mixer(uint16_t publish_time) {
    publish_time_mixer_ = publish_time * 1000; // convert to milliseconds
}

void Mqtt::set_publish_time_other(uint16_t publish_time) {
    publish_time_other_ = publish_time * 1000; // convert to milliseconds
}

void Mqtt::set_publish_time_sensor(uint16_t publish_time) {
    publish_time_sensor_ = publish_time * 1000; // convert to milliseconds
}

void Mqtt::set_publish_time_heartbeat(uint16_t publish_time) {
    publish_time_heartbeat_ = publish_time * 1000; // convert to milliseconds
}

bool Mqtt::get_publish_onchange(uint8_t device_type) {
    if (publish_single_ && !ha_enabled_) {
        return false;
    }
    if (device_type == EMSdevice::DeviceType::BOILER) {
        if (!publish_time_boiler_) {
            return true;
        }
    } else if (device_type == EMSdevice::DeviceType::THERMOSTAT) {
        if (!publish_time_thermostat_) {
            return true;
        }
    } else if (device_type == EMSdevice::DeviceType::SOLAR) {
        if (!publish_time_solar_) {
            return true;
        }
    } else if (device_type == EMSdevice::DeviceType::MIXER) {
        if (!publish_time_mixer_) {
            return true;
        }
    } else if (!publish_time_other_) {
        return true;
    }
    return false;
}
void Mqtt::on_disconnect(espMqttClientTypes::DisconnectReason reason) {
    // only show the error once, not every 2 seconds
    if (!connecting_) {
        return;
    }
    connecting_ = false;
    if (reason == espMqttClientTypes::DisconnectReason::TCP_DISCONNECTED) {
        LOG_WARNING("MQTT disconnected: TCP");
    } else if (reason == espMqttClientTypes::DisconnectReason::MQTT_UNACCEPTABLE_PROTOCOL_VERSION) {
        LOG_WARNING("MQTT disconnected: Unacceptable protocol version");
    } else if (reason == espMqttClientTypes::DisconnectReason::MQTT_IDENTIFIER_REJECTED) {
        LOG_WARNING("MQTT disconnected: Identifier Rejected");
    } else if (reason == espMqttClientTypes::DisconnectReason::MQTT_SERVER_UNAVAILABLE) {
        LOG_WARNING("MQTT disconnected: Server unavailable");
    } else if (reason == espMqttClientTypes::DisconnectReason::MQTT_MALFORMED_CREDENTIALS) {
        LOG_WARNING("MQTT disconnected: Malformed credentials");
    } else if (reason == espMqttClientTypes::DisconnectReason::MQTT_NOT_AUTHORIZED) {
        LOG_WARNING("MQTT disconnected: Not authorized");
    } else if (reason == espMqttClientTypes::DisconnectReason::TLS_BAD_FINGERPRINT) {
        LOG_WARNING("MQTT disconnected: Server fingerprint invalid");
    } else {
        LOG_WARNING("MQTT disconnected: code %d", reason);
    }
    mqttClient_->clearQueue(true);
}

// MQTT on_connect - when an MQTT connect is established
void Mqtt::on_connect() {
    if (connecting_) {
        return; // prevent duplicated connections
    }

    LOG_INFO("MQTT connected");

    connecting_ = true;
    connectcount_++; // count # reconnects. not currently used.
    queuecount_ = mqttClient_->queueSize();

    load_settings(); // reload MQTT settings - in case they have changes

    if (ha_enabled_) {
        queue_unsubscribe_message(discovery_prefix_ + "/+/" + mqtt_basename_ + "/#");
        EMSESP::reset_mqtt_ha(); // re-create all HA devices if there are any
        ha_status();             // create the EMS-ESP device in HA, which is MQTT retained
        ha_climate_reset(true);
    } else {
        // with disabled HA we subscribe and the broker sends all stored HA-emsesp-configs.
        // Around line 272 they are removed (search for "// remove HA topics if we don't use discover")
        // If HA is enabled the subscriptions are removed.
        // As described in the doc (https://emsesp.github.io/docs/#/Troubleshooting?id=home-assistant):
        // disable HA, wait 5 minutes (to allow the broker to send all), than reenable HA again.
        queue_subscribe_message(discovery_prefix_ + "/+/" + mqtt_basename_ + "/#");
    }

    // send initial MQTT messages for some of our services
    EMSESP::shower_.set_shower_state(false, true); // Send shower_activated as false
    EMSESP::system_.send_heartbeat();              // send heartbeat

    // re-subscribe to all custom registered MQTT topics
    resubscribe();

    // publish to the last will topic (see Mqtt::start() function) to say we're alive
    queue_publish_retain("status", "online", true); // with retain on

    // mqtt_publish_fails_ = 0; // reset fail count to 0
}

// Home Assistant Discovery - the main master Device called EMS-ESP
// e.g. homeassistant/sensor/ems-esp/status/config
// all the values from the heartbeat payload will be added as attributes to the entity state
void Mqtt::ha_status() {
    StaticJsonDocument<EMSESP_JSON_SIZE_LARGE> doc;

    char uniq[70];
    if (Mqtt::entity_format() == entityFormat::MULTI_SHORT) {
        snprintf(uniq, sizeof(uniq), "%s_system_status", Mqtt::basename().c_str());
    } else {
        strcpy(uniq, "system_status");
    }

    doc["uniq_id"] = uniq;
    doc["obj_id"]  = uniq;

    doc["stat_t"]   = Mqtt::base() + "/status";
    doc["name"]     = "System status";
    doc["pl_on"]    = "online";
    doc["pl_off"]   = "offline";
    doc["stat_cla"] = "measurement";
    doc["dev_cla"]  = "connectivity";
    doc["ent_cat"]  = "diagnostic";

    // doc["avty_t"]      = "~/status"; // commented out, as it causes errors in HA sometimes
    // doc["json_attr_t"] = "~/heartbeat"; // store also as HA attributes

    JsonObject dev = doc.createNestedObject("dev");
    dev["name"]    = Mqtt::basename();
    dev["sw"]      = "v" + std::string(EMSESP_APP_VERSION);
    dev["mf"]      = "proddy";
    dev["mdl"]     = "EMS-ESP";
#ifndef EMSESP_STANDALONE
    dev["cu"] = "http://" + (EMSESP::system_.ethernet_connected() ? ETH.localIP().toString() : WiFi.localIP().toString());
#endif
    JsonArray ids = dev.createNestedArray("ids");
    ids.add(Mqtt::basename());

    char topic[MQTT_TOPIC_MAX_SIZE];
    snprintf(topic, sizeof(topic), "binary_sensor/%s/system_status/config", mqtt_basename_.c_str());
    Mqtt::queue_ha(topic, doc.as<JsonObject>()); // publish the config payload with retain flag

// create the sensors - must match the MQTT payload keys
// these are all from the heartbeat MQTT topic
#ifndef EMSESP_STANDALONE
    if (!EMSESP::system_.ethernet_connected() || WiFi.isConnected()) {
        publish_system_ha_sensor_config(DeviceValueType::INT, "WiFi RSSI", "rssi", DeviceValueUOM::DBM);
        publish_system_ha_sensor_config(DeviceValueType::INT, "WiFi strength", "wifistrength", DeviceValueUOM::PERCENT);
    }
#endif

    publish_system_ha_sensor_config(DeviceValueType::STRING, "EMS Bus", "bus_status", DeviceValueUOM::NONE);
    publish_system_ha_sensor_config(DeviceValueType::STRING, "Uptime", "uptime", DeviceValueUOM::NONE);
    publish_system_ha_sensor_config(DeviceValueType::INT, "Uptime (sec)", "uptime_sec", DeviceValueUOM::SECONDS);
    publish_system_ha_sensor_config(DeviceValueType::BOOL, "NTP status", "ntp_status", DeviceValueUOM::CONNECTIVITY);
    publish_system_ha_sensor_config(DeviceValueType::INT, "Free memory", "freemem", DeviceValueUOM::KB);
    publish_system_ha_sensor_config(DeviceValueType::INT, "Max Alloc", "max_alloc", DeviceValueUOM::KB);
    publish_system_ha_sensor_config(DeviceValueType::INT, "MQTT fails", "mqttfails", DeviceValueUOM::NONE);
    publish_system_ha_sensor_config(DeviceValueType::INT, "Rx received", "rxreceived", DeviceValueUOM::NONE);
    publish_system_ha_sensor_config(DeviceValueType::INT, "Rx fails", "rxfails", DeviceValueUOM::NONE);
    publish_system_ha_sensor_config(DeviceValueType::INT, "Tx reads", "txreads", DeviceValueUOM::NONE);
    publish_system_ha_sensor_config(DeviceValueType::INT, "Tx writes", "txwrites", DeviceValueUOM::NONE);
    publish_system_ha_sensor_config(DeviceValueType::INT, "Tx fails", "txfails", DeviceValueUOM::NONE);
}

// add sub or pub task to the queue.
// the base is not included in the topic
bool Mqtt::queue_message(const uint8_t operation, const std::string & topic, const std::string & payload, const bool retain) {
    if (topic == "response" && operation == Operation::PUBLISH) {
        lastresponse_ = payload;
        if (!send_response_) {
            return true;
        }
    }
    if (!mqtt_enabled_ || topic.empty() || !connected()) {
        return false; // quit, not using MQTT
    }
// check free mem
#ifndef EMSESP_STANDALONE
    if (ESP.getFreeHeap() < 60 * 1204 || ESP.getMaxAllocHeap() < 40 * 1024) {
        if (operation == Operation::PUBLISH) {
            mqtt_message_id_++;
            mqtt_publish_fails_++;
        }
        LOG_WARNING("%s failed: low memory", operation == Operation::PUBLISH ? "Publish" : operation == Operation::SUBSCRIBE ? "Subscribe" : "Unsubscribe");
        return false; // quit
    }
    if (queuecount_ >= MQTT_QUEUE_MAX_SIZE) {
        if (operation == Operation::PUBLISH) {
            mqtt_message_id_++;
            mqtt_publish_fails_++;
        }
        LOG_WARNING("%s failed: queue full", operation == Operation::PUBLISH ? "Publish" : operation == Operation::SUBSCRIBE ? "Subscribe" : "Unsubscribe");
        return false; // quit
    }
#endif

    uint16_t packet_id = 0;
    char     fulltopic[MQTT_TOPIC_MAX_SIZE];

    if (topic.find(discovery_prefix_) == 0) {
        strlcpy(fulltopic, topic.c_str(), sizeof(fulltopic)); // leave discovery topic as it is
    } else {
        // it's not a discovery topic, added the mqtt base to the topic path
        snprintf(fulltopic, sizeof(fulltopic), "%s/%s", Mqtt::base().c_str(), topic.c_str());
    }

    if (operation == Operation::PUBLISH) {
        packet_id = mqttClient_->publish(fulltopic, mqtt_qos_, retain, payload.c_str());
        mqtt_message_id_++;
        LOG_DEBUG("Publishing topic '%s', pid %d", fulltopic, packet_id);
    } else if (operation == Operation::SUBSCRIBE) {
        packet_id = mqttClient_->subscribe(fulltopic, mqtt_qos_);
        LOG_DEBUG("Subscribing to topic '%s', pid %d", fulltopic, packet_id);
    } else if (operation == Operation::UNSUBSCRIBE) {
        packet_id = mqttClient_->unsubscribe(fulltopic);
        LOG_DEBUG("Unsubscribing to topic '%s', pid %d", fulltopic, packet_id);
    }
#ifndef EMSESP_STANDALONE
    if (packet_id == 0) {
        LOG_WARNING("%s failed: %s", operation == Operation::PUBLISH ? "Publish" : operation == Operation::SUBSCRIBE ? "Subscribe" : "Unsubscribe", fulltopic);
        mqtt_publish_fails_++;
    }
#endif
    return (packet_id != 0);
}

// add MQTT message to queue, payload is a string
bool Mqtt::queue_publish_message(const std::string & topic, const std::string & payload, const bool retain) {
    return queue_message(Operation::PUBLISH, topic, payload, retain);
}

// add MQTT subscribe message to queue
void Mqtt::queue_subscribe_message(const std::string & topic) {
    queue_message(Operation::SUBSCRIBE, topic, "", false); // no payload
}

// add MQTT unsubscribe message to queue
void Mqtt::queue_unsubscribe_message(const std::string & topic) {
    queue_message(Operation::UNSUBSCRIBE, topic, "", false); // no payload
}

// MQTT Publish, using a user's retain flag
bool Mqtt::queue_publish(const std::string & topic, const std::string & payload) {
    return queue_publish_message(topic, payload, mqtt_retain_);
}

// MQTT Publish, using a user's retain flag - except for char * strings
bool Mqtt::queue_publish(const char * topic, const char * payload) {
    return queue_publish_message((topic), payload, mqtt_retain_);
}

// MQTT Publish, using a specific retain flag, topic is a flash string
bool Mqtt::queue_publish(const char * topic, const std::string & payload) {
    return queue_publish_message((topic), payload, mqtt_retain_);
}

bool Mqtt::queue_publish(const char * topic, const JsonObject & payload) {
    return queue_publish_retain(topic, payload, mqtt_retain_);
}

// publish json doc, only if its not empty
bool Mqtt::queue_publish(const std::string & topic, const JsonObject & payload) {
    return queue_publish_retain(topic, payload, mqtt_retain_);
}

// MQTT Publish, using a specific retain flag, topic is a flash string, forcing retain flag
bool Mqtt::queue_publish_retain(const char * topic, const std::string & payload, const bool retain) {
    return queue_publish_message((topic), payload, retain);
}

// publish json doc, only if its not empty, using the retain flag
bool Mqtt::queue_publish_retain(const std::string & topic, const JsonObject & payload, const bool retain) {
    return queue_publish_retain(topic.c_str(), payload, retain);
}

bool Mqtt::queue_publish_retain(const char * topic, const JsonObject & payload, const bool retain) {
    if (payload.size()) {
        std::string payload_text;
        payload_text.reserve(measureJson(payload) + 1);
        serializeJson(payload, payload_text); // convert json to string
        return queue_publish_message(topic, payload_text, retain);
    }
    return false;
}

// publish empty payload to remove the topic
bool Mqtt::queue_remove_topic(const char * topic) {
    if (ha_enabled_) {
        return queue_publish_message(Mqtt::discovery_prefix() + topic, "", true); // publish with retain to remove from broker
    } else {
        return queue_publish_message(topic, "", true); // publish with retain to remove from broker
    }
}

// queue a Home Assistant config topic and payload, with retain flag off.
bool Mqtt::queue_ha(const char * topic, const JsonObject & payload) {
    if (!enabled()) {
        return false;
    }

    std::string payload_text;
    payload_text.reserve(measureJson(payload) + 1);
    serializeJson(payload, payload_text); // convert json to string

    return queue_publish_message(Mqtt::discovery_prefix() + topic, payload_text, true); // with retain true
}

// create's a ha sensor config topic from a device value object
// and also takes a flag (create_device_config) used to also create the main HA device config. This is only needed for one entity
bool Mqtt::publish_ha_sensor_config(DeviceValue & dv, const char * model, const char * brand, const bool remove, const bool create_device_config) {
    StaticJsonDocument<EMSESP_JSON_SIZE_LARGE> dev_json;

    // always create the ids (discovery indentifiers)
    // with the name always
    // and the manufacturer and model if we're creating the device config for the first entity
    JsonArray ids = dev_json.createNestedArray("ids");
    char      ha_device[40];
    auto      device_type_name = EMSdevice::device_type_2_device_name(dv.device_type);
    snprintf(ha_device, sizeof(ha_device), "%s-%s", Mqtt::basename().c_str(), device_type_name);
    ids.add(ha_device);

    auto cap_name = strdup(device_type_name);
    Helpers::CharToUpperUTF8(cap_name); // capitalize first letter
    dev_json["name"] = Mqtt::basename() + " " + cap_name;
    free(cap_name);

    if (create_device_config) {
        dev_json["mf"]         = brand;
        dev_json["mdl"]        = model;
        dev_json["via_device"] = "ems-esp";
    }

    // calculate the min and max
    int16_t  dv_set_min;
    uint32_t dv_set_max;
    (void)dv.get_min_max(dv_set_min, dv_set_max);

    // determine if we're creating the command topics which we use special HA configs
    // unless the entity has been marked as read-only and so it'll default to using the sensor/ type
    // or we're dealing with Energy sensors that must have "diagnostic" as an entity category (e.g. negheat & nrgww)
    bool has_cmd = dv.has_cmd && !dv.has_state(DeviceValueState::DV_READONLY) && (dv.uom != DeviceValueUOM::KWH);

    return publish_ha_sensor_config(dv.type,
                                    dv.tag,
                                    dv.get_fullname().c_str(),
                                    (dv.fullname ? dv.fullname[0] : nullptr), // EN name
                                    dv.device_type,
                                    dv.short_name,
                                    dv.uom,
                                    remove,
                                    has_cmd,
                                    dv.options,
                                    dv.options_size,
                                    dv_set_min,
                                    dv_set_max,
                                    dv.numeric_operator,
                                    dev_json.as<JsonObject>());
}

// publish HA sensor for System using the heartbeat tag
bool Mqtt::publish_system_ha_sensor_config(uint8_t type, const char * name, const char * entity, const uint8_t uom) {
    StaticJsonDocument<EMSESP_JSON_SIZE_LARGE> doc;
    JsonObject                                 dev_json = doc.createNestedObject("dev");

    dev_json["name"] = Mqtt::basename();
    JsonArray ids    = dev_json.createNestedArray("ids");
    ids.add(Mqtt::basename());

    return publish_ha_sensor_config(
        type, DeviceValueTAG::TAG_HEARTBEAT, name, name, EMSdevice::DeviceType::SYSTEM, entity, uom, false, false, nullptr, 0, 0, 0, 0, dev_json);
}

// MQTT discovery configs
// entity must match the key/value pair in the *_data topic
// note: some extra string copying done here, it looks messy but does help with heap fragmentation issues
bool Mqtt::publish_ha_sensor_config(uint8_t               type,        // EMSdevice::DeviceValueType
                                    uint8_t               tag,         // EMSdevice::DeviceValueTAG
                                    const char * const    fullname,    // fullname, already translated
                                    const char * const    en_name,     // original name in english
                                    const uint8_t         device_type, // EMSdevice::DeviceType
                                    const char * const    entity,      // same as shortname
                                    const uint8_t         uom,         // EMSdevice::DeviceValueUOM (0=NONE)
                                    const bool            remove,      // true if we want to remove this topic
                                    const bool            has_cmd,
                                    const char * const ** options,
                                    uint8_t               options_size,
                                    const int16_t         dv_set_min,
                                    const uint32_t        dv_set_max,
                                    const int8_t          num_op,
                                    const JsonObject &    dev_json) {
    // ignore if name (fullname) is empty
    if (!fullname || !en_name) {
        return false;
    }

    // create the device name
    auto device_name = EMSdevice::device_type_2_device_name(device_type);

    bool has_tag = ((tag < DeviceValue::NUM_TAGS) && (tag != DeviceValue::DeviceValueTAG::TAG_NONE) && strlen(DeviceValue::DeviceValueTAG_s[tag][0]));

    // create entity by add the hc/wwc tag if present, separating with an _
    char entity_with_tag[50];
    if (tag >= DeviceValueTAG::TAG_HC1) {
        snprintf(entity_with_tag, sizeof(entity_with_tag), "%s_%s", EMSdevice::tag_to_mqtt(tag), entity);
    } else {
        snprintf(entity_with_tag, sizeof(entity_with_tag), "%s", entity);
    }

    // build unique identifier also used as object_id which also becomes the Entity ID in HA
    char uniq_id[80];
    if (Mqtt::entity_format() == entityFormat::MULTI_SHORT) {
        // prefix base name to each uniq_id and use the shortname
        snprintf(uniq_id, sizeof(uniq_id), "%s_%s_%s", mqtt_basename_.c_str(), device_name, entity_with_tag);
    } else if (Mqtt::entity_format() == entityFormat::SINGLE_SHORT) {
        // shortname, no mqtt base. This is the default version.
        snprintf(uniq_id, sizeof(uniq_id), "%s_%s", device_name, entity_with_tag);
    } else {
        // entity_format is 0, the old v3.4 style
        // take en_name and replace all spaces
        char uniq_s[60];
        strlcpy(uniq_s, en_name, sizeof(uniq_s));
        Helpers::replace_char(uniq_s, ' ', '_');
        Helpers::replace_char(uniq_s, '+', '2'); //changes 'eco+_switch_off' to 'eco2_switch_off' (HA ignores '+')
        if (has_tag) {
            snprintf(uniq_id, sizeof(uniq_id), "%s_%s_%s", device_name, DeviceValue::DeviceValueTAG_s[tag][0], Helpers::toLower(uniq_s).c_str());
        } else {
            snprintf(uniq_id, sizeof(uniq_id), "%s_%s", device_name, Helpers::toLower(uniq_s).c_str());
        }
    }

    // build a config topic that will be prefix onto a HA type (e.g. number, switch)
    char config_topic[70];
    snprintf(config_topic, sizeof(config_topic), "%s/%s_%s/config", mqtt_basename_.c_str(), device_name, entity_with_tag);

    bool readonly_sensors = true;

    // create the topic
    // depending on the type and whether the device entity is writable (a command)
    // https://developers.home-assistant.io/docs/core/entity
    char topic[MQTT_TOPIC_MAX_SIZE];
    // if it's a command then we can use Number, Switch, Select or Text. Otherwise stick to Sensor
    if (has_cmd) {
        switch (type) {
        case DeviceValueType::INT:
        case DeviceValueType::UINT:
        case DeviceValueType::SHORT:
        case DeviceValueType::USHORT:
        case DeviceValueType::ULONG:
            // number - https://www.home-assistant.io/integrations/number.mqtt
            // Domoticz does not support number, use sensor
            if (discovery_type() == discoveryType::HOMEASSISTANT) {
                snprintf(topic, sizeof(topic), "number/%s", config_topic);
                readonly_sensors = false;
            } else {
                snprintf(topic, sizeof(topic), "sensor/%s", config_topic);
            }
            break;
        case DeviceValueType::BOOL:
            // switch - https://www.home-assistant.io/integrations/switch.mqtt
            snprintf(topic, sizeof(topic), "switch/%s", config_topic);
            readonly_sensors = false;
            break;
        case DeviceValueType::ENUM:
            // select - https://www.home-assistant.io/integrations/select.mqtt
            snprintf(topic, sizeof(topic), "select/%s", config_topic);
            readonly_sensors = false;
            break;
        case DeviceValueType::STRING:
            // text - https://www.home-assistant.io/integrations/text.mqtt
            snprintf(topic, sizeof(topic), "text/%s", config_topic); // e.g. set_datetime, set_holiday, set_wwswitchtime
            readonly_sensors = false;
            break;
        default:
            // plain old sensor, and make read-only
            break;
        }
    }

    // For read-only sensors there are either sensor or binary_sensor
    // for both we also set the device class and state class
    if (readonly_sensors) {
        snprintf(topic, sizeof(topic), (type == DeviceValueType::BOOL) ? "binary_sensor/%s" : "sensor/%s", config_topic); // binary sensor (for booleans)
    }

    // if we're asking to remove this topic, send an empty payload and exit
    // https://github.com/emsesp/EMS-ESP32/issues/196
    if (remove) {
        LOG_DEBUG("Queuing removing topic %s", topic);
        return queue_remove_topic(topic);
    }

    // build the payload
    StaticJsonDocument<EMSESP_JSON_SIZE_LARGE> doc;
    doc["uniq_id"] = uniq_id;
    doc["obj_id"]  = uniq_id; // same as unique_id

    const char * ic_ha  = "ic";           // icon - only set this if there is no device class
    const char * uom_ha = "unit_of_meas"; // unit of measure

    char sample_val[30] = "0"; // sample, correct(!) entity value, used only to prevent warning/error in HA if real value is not published yet

    // we add the command topic parameter for commands
    if (has_cmd) {
        // add category
        // doc["ent_cat"] = "config"; // for writeable entities, like switch, number, text, select

        char command_topic[MQTT_TOPIC_MAX_SIZE];
        // add command topic
        if (tag >= DeviceValueTAG::TAG_HC1) {
            snprintf(command_topic, sizeof(command_topic), "%s/%s/%s/%s", mqtt_basename_.c_str(), device_name, EMSdevice::tag_to_mqtt(tag), entity);
        } else {
            snprintf(command_topic, sizeof(command_topic), "%s/%s/%s", mqtt_basename_.c_str(), device_name, entity);
        }
        doc["cmd_t"] = command_topic;

        // extend for enums, add options
        if (type == DeviceValueType::ENUM) {
            JsonArray option_list = doc.createNestedArray("ops"); // options
            if (EMSESP::system_.enum_format() == ENUM_FORMAT_INDEX) {
                // use index numbers
                for (uint8_t i = 0; i < options_size; i++) {
                    option_list.add(Helpers::itoa(i)); // as a string
                }
                snprintf(sample_val, sizeof(sample_val), "'0'");
            } else {
                // use strings
                for (uint8_t i = 0; i < options_size; i++) {
                    option_list.add(Helpers::translated_word(options[i]));
                }
                snprintf(sample_val, sizeof(sample_val), "'%s'", Helpers::translated_word(options[0]));
            }

        } else if (type != DeviceValueType::STRING && type != DeviceValueType::BOOL) {
            // For numeric's add the range
            doc["mode"] = "box"; // auto, slider or box
            if (num_op > 0) {
                doc["step"] = 1.0 / num_op;
            } else if (num_op < 0) {
                doc["step"] = -num_op;
            } else {
                doc["step"] = 1;
            }
        }

        // set min and max values, if we have a valid range
        if (dv_set_min != 0 || dv_set_max != 0) {
            doc["min"] = dv_set_min;
            doc["max"] = dv_set_max;
            snprintf(sample_val, sizeof(sample_val), "%i", dv_set_min);
        }

        // set icons
        // since these don't have a device class we need to add the icon ourselves
        switch (uom) {
        case DeviceValueUOM::DEGREES:
        case DeviceValueUOM::DEGREES_R:
        case DeviceValueUOM::K:
            doc[ic_ha] = F_(icondegrees);
            break;
        case DeviceValueUOM::PERCENT:
            doc[ic_ha] = F_(iconpercent);
            break;
        default:
            break;
        }
    }

    // state topic
    char stat_t[MQTT_TOPIC_MAX_SIZE];
    snprintf(stat_t, sizeof(stat_t), "%s/%s", Mqtt::base().c_str(), tag_to_topic(device_type, tag).c_str());
    doc["stat_t"] = stat_t;

    // friendly name = <tag> <name>
    char   ha_name[70];
    char * F_name = strdup(fullname);
    Helpers::CharToUpperUTF8(F_name); // capitalize first letter
    if (has_tag) {
        // exclude heartbeat tag
        snprintf(ha_name, sizeof(ha_name), "%s %s", EMSdevice::tag_to_string(tag), F_name);
    } else {
        snprintf(ha_name, sizeof(ha_name), "%s", F_name); // no tag
    }
    free(F_name); // very important!
    doc["name"] = ha_name;

    // value template
    // if its nested mqtt format then use the appended entity name, otherwise take the original name
    char val_obj[100];
    char val_cond[200];
    if (is_nested() && tag >= DeviceValueTAG::TAG_HC1) {
        snprintf(val_obj, sizeof(val_obj), "value_json.%s.%s", EMSdevice::tag_to_mqtt(tag), entity);
        snprintf(val_cond, sizeof(val_cond), "value_json.%s is defined and %s is defined", EMSdevice::tag_to_mqtt(tag), val_obj);
    } else {
        snprintf(val_obj, sizeof(val_obj), "value_json.%s", entity);
        snprintf(val_cond, sizeof(val_cond), "%s is defined", val_obj);
    }

    // special case to handle booleans
    // applies to both Binary Sensor (read only) and a Switch (for a command)
    // has no unit of measure or icon
    if (type == DeviceValueType::BOOL) {
        if (EMSESP::system_.bool_format() == BOOL_FORMAT_TRUEFALSE) {
            doc["pl_on"]  = true;
            doc["pl_off"] = false;
            snprintf(sample_val, sizeof(sample_val), "false");
        } else if (EMSESP::system_.bool_format() == BOOL_FORMAT_10) {
            doc["pl_on"]  = 1;
            doc["pl_off"] = 0;
        } else {
            char result[12];
            doc["pl_on"]  = Helpers::render_boolean(result, true);
            doc["pl_off"] = Helpers::render_boolean(result, false);
            snprintf(sample_val, sizeof(sample_val), "'%s'", Helpers::render_boolean(result, false));
        }
    } else {
        // always set the uom, using the standards except for hours/minutes/seconds
        // using HA specific codes from https://github.com/home-assistant/core/blob/dev/homeassistant/const.py
        if (uom == DeviceValueUOM::HOURS) {
            doc[uom_ha] = "h";
        } else if (uom == DeviceValueUOM::MINUTES) {
            doc[uom_ha] = "min";
        } else if (uom == DeviceValueUOM::SECONDS) {
            doc[uom_ha] = "s";
        } else if (uom != DeviceValueUOM::NONE) {
            doc[uom_ha] = EMSdevice::uom_to_string(uom); // default
        }
    }

    doc["val_tpl"] = (std::string) "{{" + val_obj + " if " + val_cond + " else " + sample_val + "}}";

    // Add the state class, device class and sometimes the icon. Used only for read-only sensors Sensor and Binary Sensor
    if (readonly_sensors) {
        // first set the catagory for System entities
        // https://github.com/emsesp/EMS-ESP32/discussions/1459#discussioncomment-7694873
        if (device_type == EMSdevice::DeviceType::SYSTEM) {
            doc["ent_cat"] = "diagnostic";
        }

        const char * dc_ha = "dev_cla";  // device class
        const char * sc_ha = "stat_cla"; // state class

        switch (uom) {
        case DeviceValueUOM::DEGREES:
        case DeviceValueUOM::DEGREES_R:
        case DeviceValueUOM::K:
            doc[sc_ha] = F_(measurement);
            doc[dc_ha] = "temperature"; // no icon needed
            break;
        case DeviceValueUOM::PERCENT:
            doc[sc_ha] = F_(measurement);
            doc[dc_ha] = "power_factor"; // no icon needed
            break;
        case DeviceValueUOM::SECONDS:
        case DeviceValueUOM::MINUTES:
        case DeviceValueUOM::HOURS:
            if (type == DeviceValueType::TIME) {
                doc[sc_ha] = F_(total_increasing);
            } else {
                doc[sc_ha] = F_(measurement);
            }
            doc[dc_ha] = "duration"; // https://github.com/emsesp/EMS-ESP32/issues/822
            break;
        case DeviceValueUOM::KB:
            doc[ic_ha] = F_(iconkb);
            break;
        case DeviceValueUOM::LMIN:
            doc[ic_ha] = F_(iconlmin);
            doc[sc_ha] = F_(measurement);
            break;
        case DeviceValueUOM::WH:
            if (entity == FL_(energyToday)[0]) {
                doc[sc_ha] = F_(total_increasing);
            } else {
                doc[sc_ha] = F_(measurement);
            }
            doc[dc_ha] = "energy";
            break;
        case DeviceValueUOM::KWH:
            doc[sc_ha] = F_(total_increasing);
            doc[dc_ha] = "energy";
            break;
        case DeviceValueUOM::UA:
            doc[ic_ha] = F_(iconua);
            doc[sc_ha] = F_(measurement);
            break;
        case DeviceValueUOM::BAR:
            doc[sc_ha] = F_(measurement);
            doc[dc_ha] = "pressure";
            break;
        case DeviceValueUOM::W:
        case DeviceValueUOM::KW:
            doc[sc_ha] = F_(measurement);
            doc[dc_ha] = "power";
            break;
        case DeviceValueUOM::DBM:
            doc[sc_ha] = F_(measurement);
            doc[dc_ha] = "signal_strength";
            break;
        case DeviceValueUOM::CONNECTIVITY:
            doc[sc_ha] = F_(measurement);
            doc[dc_ha] = "connectivity";
            break;
        case DeviceValueUOM::NONE:
            // for device entities which have numerical values, with no UOM
            if ((type != DeviceValueType::STRING)
                && (type == DeviceValueType::INT || type == DeviceValueType::UINT || type == DeviceValueType::SHORT || type == DeviceValueType::USHORT
                    || type == DeviceValueType::ULONG)) {
                doc[ic_ha] = F_(iconnum); // set icon
                // determine if its a measurement or total increasing
                // most of the values are measurement. for example Tx Reads will increment but can be reset to 0 after a restart
                // all the starts are increasing, and they are ULONGs
                if (type == DeviceValueType::ULONG) {
                    doc[sc_ha] = F_(total_increasing);
                } else {
                    doc[sc_ha] = F_(measurement); // default to measurement
                }
            }
            break;
        default:
            break;
        }
    }

    doc["dev"] = dev_json;                                   // add the dev json object to the end
    add_avty_to_doc(stat_t, doc.as<JsonObject>(), val_cond); // add "availability" section

    return queue_ha(topic, doc.as<JsonObject>());
}

bool Mqtt::publish_ha_climate_config(const uint8_t tag, const bool has_roomtemp, const bool remove, const int16_t min, const uint32_t max) {
    uint8_t hc_num = tag - DeviceValueTAG::TAG_HC1 + 1;

    char topic[Mqtt::MQTT_TOPIC_MAX_SIZE];
    char topic_t[Mqtt::MQTT_TOPIC_MAX_SIZE];
    char hc_mode_s[30];
    char seltemp_s[30];
    char currtemp_s[30];
    char hc_mode_cond[80];
    char seltemp_cond[100];
    char currtemp_cond[100];
    char mode_str_tpl[400];
    char name_s[10];
    char uniq_id_s[60];
    char temp_cmd_s[30];
    char mode_cmd_s[30];
    char min_s[10];
    char max_s[10];

    snprintf(topic, sizeof(topic), "climate/%s/thermostat_hc%d/config", Mqtt::basename().c_str(), hc_num);
    if (remove) {
        return queue_remove_topic(topic); // publish empty payload with retain flag
    }

    if (Mqtt::is_nested()) {
        // nested format
        snprintf(hc_mode_s, sizeof(hc_mode_s), "value_json.hc%d.mode", hc_num);
        snprintf(hc_mode_cond, sizeof(hc_mode_cond), "value_json.hc%d is undefined or %s is undefined", hc_num, hc_mode_s);
        snprintf(seltemp_s, sizeof(seltemp_s), "value_json.hc%d.seltemp", hc_num);
        snprintf(seltemp_cond, sizeof(seltemp_cond), "value_json.hc%d is defined and %s is defined", hc_num, seltemp_s);

        if (has_roomtemp) {
            snprintf(currtemp_s, sizeof(currtemp_s), "value_json.hc%d.currtemp", hc_num);
            snprintf(currtemp_cond, sizeof(currtemp_cond), "value_json.hc%d is defined and %s is defined", hc_num, currtemp_s);
        }
        snprintf(topic_t, sizeof(topic_t), "~/%s", Mqtt::tag_to_topic(EMSdevice::DeviceType::THERMOSTAT, DeviceValueTAG::TAG_NONE).c_str());
    } else {
        // single format
        snprintf(hc_mode_s, sizeof(hc_mode_s), "value_json.mode");
        snprintf(hc_mode_cond, sizeof(hc_mode_cond), "%s is undefined", hc_mode_s);
        snprintf(seltemp_s, sizeof(seltemp_s), "value_json.seltemp");
        snprintf(seltemp_cond, sizeof(seltemp_cond), "%s is defined", seltemp_s);

        if (has_roomtemp) {
            snprintf(currtemp_s, sizeof(currtemp_s), "value_json.currtemp");
            snprintf(currtemp_cond, sizeof(currtemp_cond), "%s is defined", currtemp_s);
        }
        snprintf(topic_t, sizeof(topic_t), "~/%s", Mqtt::tag_to_topic(EMSdevice::DeviceType::THERMOSTAT, DeviceValueTAG::TAG_HC1 + hc_num - 1).c_str());
    }

    snprintf(mode_str_tpl,
             sizeof(mode_str_tpl),
             "{%%if %s%%}off{%%elif %s=='%s'%%}heat{%%elif %s=='%s'%%}heat{%%elif %s=='%s'%%}off{%%elif %s=='%s'%%}off{%%else%%}auto{%%endif%%}",
             hc_mode_cond,
             hc_mode_s,
             Helpers::translated_word(FL_(manual)),
             hc_mode_s,
             Helpers::translated_word(FL_(day)),
             hc_mode_s,
             Helpers::translated_word(FL_(night)),
             hc_mode_s,
             Helpers::translated_word(FL_(off)));

    snprintf(name_s, sizeof(name_s), "Hc%d", hc_num);

    if (Mqtt::entity_format() == entityFormat::MULTI_SHORT) {
        snprintf(uniq_id_s, sizeof(uniq_id_s), "%s_thermostat_hc%d", Mqtt::basename().c_str(), hc_num); // add basename
    } else {
        snprintf(uniq_id_s, sizeof(uniq_id_s), "thermostat_hc%d", hc_num); // backward compatible with v3.4
    }

    snprintf(temp_cmd_s, sizeof(temp_cmd_s), "~/thermostat/hc%d/seltemp", hc_num);
    snprintf(mode_cmd_s, sizeof(mode_cmd_s), "~/thermostat/hc%d/mode", hc_num);

    StaticJsonDocument<EMSESP_JSON_SIZE_XLARGE> doc; // 1024 is not enough

    doc["~"]             = Mqtt::base();
    doc["uniq_id"]       = uniq_id_s;
    doc["obj_id"]        = uniq_id_s; // same as uniq_id
    doc["name"]          = name_s;
    doc["mode_stat_t"]   = topic_t;
    doc["mode_stat_tpl"] = mode_str_tpl;
    doc["temp_cmd_t"]    = temp_cmd_s;
    doc["temp_stat_t"]   = topic_t;
    doc["temp_stat_tpl"] = (std::string) "{{" + seltemp_s + " if " + seltemp_cond + " else 0}}";

    if (has_roomtemp) {
        doc["curr_temp_t"]   = topic_t;
        doc["curr_temp_tpl"] = (std::string) "{{" + currtemp_s + " if " + currtemp_cond + " else 0}}";
    }

    doc["min_temp"]   = Helpers::render_value(min_s, min, 0, EMSESP::system_.fahrenheit() ? 2 : 0);
    doc["max_temp"]   = Helpers::render_value(max_s, max, 0, EMSESP::system_.fahrenheit() ? 2 : 0);
    doc["temp_step"]  = "0.5";
    doc["mode_cmd_t"] = mode_cmd_s;

    // the HA climate component only responds to auto, heat and off
    JsonArray modes = doc.createNestedArray("modes");

    modes.add("auto");
    modes.add("heat");
    modes.add("off");

    JsonObject dev = doc.createNestedObject("dev");
    JsonArray  ids = dev.createNestedArray("ids");

    char ha_device[40];
    snprintf(ha_device, sizeof(ha_device), "%s-thermostat", Mqtt::basename().c_str());
    ids.add(ha_device);

    // device name must be different to the entity name, take the ids value we just created
    dev["name"] = ha_device;

    // add "availability" section
    add_avty_to_doc(topic_t, doc.as<JsonObject>(), seltemp_cond, has_roomtemp ? currtemp_cond : nullptr, hc_mode_cond);

    return queue_ha(topic, doc.as<JsonObject>()); // publish the config payload with retain flag
}

// based on the device and tag, create the MQTT topic name (without the basename)
// differs based on whether MQTT nested is enabled
// tag = EMSdevice::DeviceValueTAG
std::string Mqtt::tag_to_topic(uint8_t device_type, uint8_t tag) {
    // the system device is treated differently. The topic is 'heartbeat' and doesn't follow the usual convention
    if (device_type == EMSdevice::DeviceType::SYSTEM) {
        return EMSdevice::tag_to_mqtt(tag);
    }

    std::string topic = EMSdevice::device_type_2_device_name(device_type);

    // if there is a tag add it
    if ((tag == DeviceValueTAG::TAG_BOILER_DATA_WW) || (!is_nested() && tag >= DeviceValueTAG::TAG_HC1)) {
        return topic + "_data_" + EMSdevice::tag_to_mqtt(tag);
    } else {
        return topic + "_data";
    }
}

// adds "availability" section to HA Discovery config
void Mqtt::add_avty_to_doc(const char * state_t, const JsonObject & doc, const char * cond1, const char * cond2, const char * negcond) {
    const char * tpl_draft = "{{'online' if %s else 'offline'}}";
    char         tpl[150];
    JsonArray    avty = doc.createNestedArray("avty");

    StaticJsonDocument<512> avty_json;

    snprintf(tpl, sizeof(tpl), "%s/status", Mqtt::base().c_str());
    avty_json["t"] = tpl;
    snprintf(tpl, sizeof(tpl), tpl_draft, "value == 'online'");
    avty_json["val_tpl"] = tpl;
    avty.add(avty_json);
    avty_json.clear();
    avty_json["t"] = state_t;
    snprintf(tpl, sizeof(tpl), tpl_draft, cond1 == nullptr ? "value is defined" : cond1);
    avty_json["val_tpl"] = tpl;
    avty.add(avty_json);

    if (cond2 != nullptr) {
        avty_json.clear();
        avty_json["t"] = state_t;
        snprintf(tpl, sizeof(tpl), tpl_draft, cond2);
        avty_json["val_tpl"] = tpl;
        avty.add(avty_json);
    }

    if (negcond != nullptr) {
        avty_json.clear();
        avty_json["t"] = state_t;
        snprintf(tpl, sizeof(tpl), "{{'offline' if %s else 'online'}}", negcond);
        avty_json["val_tpl"] = tpl;
        avty.add(avty_json);
    }

    doc["avty_mode"] = "all";
}

} // namespace emsesp